How to Make a Crossword Puzzle

3 rulesdecide everything: symmetric black squares, no answer under three letters, and every square crossing two words at once.

Making a crossword looks like dropping words into a grid. It is closer to solving a logic puzzle: a few rigid rules turn a blank grid into something only a handful of arrangements can satisfy. Here is how it actually works — with a sandbox to feel the trickiest rule, and a game to practise the rest.

180°

Symmetry

3 letters

Min word

Words crossing each cell

15 x 15

Weekday grid

Feel the symmetry rule

Tap any square to make it black. Its 180-degree partner flips with it — because every real crossword grid must obey that.

0black squares

They always change in even numbers — that is symmetry doing its job. The centre square (outlined) is its own mirror.

On a real 15x15 grid you would also keep every white run three letters or longer. That constraint is what turns grid-making into a genuine puzzle.

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The five steps constructors actually use

Start with the theme

Professional grids are built around a few long theme answers placed first, almost always in symmetric positions. Everything else is fill that holds them together.

Place the black squares

Black squares break the grid into words. They must sit in 180-degree rotational symmetry, and they are capped so the grid stays dense and interlocked. Try the sandbox above to feel it.

Respect the three-letter floor

No answer may be shorter than three letters. That single rule kills most casual layouts, because stray two-letter slots appear the moment you get careless.

Fill so every crossing works

Each white square belongs to one Across and one Down answer, so every letter has to satisfy two words at once. This is the hard part, and where constructors lean on word lists.

Write the clues last

Only once the grid is filled do you clue it. The same answer can be Monday-easy or Saturday-fiendish depending entirely on how you write the clue.

The part software hides from you

Grid-filling tools make crosswords feel automatic, which buries the one skill that matters: making words interlock when every shared letter has to serve two answers at once. That is exactly the muscle our word game trains.

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Skip the software — build words right here

How Many Words Can You Fit? drops a word, then challenges you to cross more onto it in a sliding grid. Long words, rare letters and three-way crosses score bonuses, with a worldwide leaderboard.

Play the word game →

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Sources

Standard crossword construction conventions — 180-degree rotational symmetry, three-letter minimum, full interlock (every white square in two answers).
The New York Times crossword guidelines — black-square limits and 15x15 / 21x21 grid sizes.
Theme-first construction workflow used by working constructors.

Frequently asked questions

How do you make a crossword puzzle?

Place a few long theme answers first, lay out 180-degree symmetric black squares, then fill the grid so every white square works as both an Across and a Down word. Clue it last.

What are the rules for a crossword grid?

No answer under three letters, 180-degree rotational symmetry of the black squares, and every white square must be part of both an Across and a Down entry. Most outlets also cap the number of black squares.

Is it hard to make a crossword?

The filling is genuinely hard, because each letter must satisfy two words at once. The black-square symmetry is the easy part once you see it, which is what the sandbox above demonstrates.

Can I make a crossword for free?

Yes. You can sketch one on paper using the rules here, or play our free in-browser word game to practise the interlocking that makes crosswords work.

How many words are in a crossword?

A standard 15x15 grid holds roughly 70 to 80 answers; a 21x21 Sunday grid around 140. The grid size sets the count.

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Anyone can drop words in a grid. A crossword is what survives once every square has to answer to two words and a mirror.

How to Make a Crossword Puzzle

Feel the symmetry rule

The five steps constructors actually use

The part software hides from you

Sources

Frequently asked questions

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